(a) Field of the Invention
The present invention relates to a metallic golf club head of so-called "iron golf club head", especially relates to hollow iron club heads from 1st to 6th iron.
(b) Description of Prior Art
One of the representative of this kind of golf club head is disclosed in Japanese Patent Laid-Open No. 60-36074, in which metal plates are press worked so that face member, upper member and side-peripheral member are formed of metallic crusts respectively, which are integrally combined so as to form a hollow head. Further, another representative is disclosed in Japanese Patent Laid-Open No. 63-154186, wherein metallic plates are press worked so that face member, upper member and upper half of side-peripheral member, and sole member and lower half of side-peripheral member are formed of metallic crusts respectively, thereby forming a hollow club head by integrally combining those metallic crusts.
Although the above-mentioned prior art mainly relate to so-called "metal wood", hollow "metal iron" have come to be utilized for iron golf club head from 1st to 6th in recent years, because such hollow metal irons have such large volume or capacity that players can get a sense of stability in hitting balls.
Whereas, it is imperative that the center of gravity of golf club heads be kept off the face, and that be lowered as close to the sole as possible to obtain the aforesaid sense of stability and enlarge so-called sweet area. To effect which, for example, the upper crust of the head is generally formed thinner, while the lower and back crust thereof is formed thicker in order that the center of gravity of the head may be positioned further backward and low. However, such method or means have had certain limitations for further desirable positioning of the center of gravity of the head.